from The Century Dictionary and Cyclopedia
- In petrography, having the characters of, containing, or relating to, phenocrysts.
Sorry, no etymologies found.
Quartz in groundmass does not appear to have nucleated directly on phenocryst, but is in optical continuity with it. (f) Primary vapor-rich fluid inclusion in phenocrystic quartz.
Feldspar compositions in the groundmass are slightly more Or-rich than the phenocrystic feldspar, which ranges from An10Or15Ab75 to about An1Or44Ab55.